Cartridge Length Issue?

kwintz

kwintz

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So i bucked up and bought the Hornady OAL Guage and the .308 to go with it.

#1 i check the distance to the lands on precision rifle and im getting 2.855" using digital calipers
#2 i check the distance to the lands in my tikka and get a whopping 2.940" using the calipers.

Now my Rcbs/Speer reloading manual has a maximum cartridge OAL of 2.810"

Those are some pretty big differences, and i tried each a couple of times, making sure not to jam the bullet into the lands....

Any helpful info/comments would be appreciated, thanks.
 
if im getting this right, all measurements are base to tip of bullet

the book measurement is just a guide, if you load for example .010'' off the lands for your tikka (2.930'') your loaded rounds might not fit in your magazine

but that would reduce the bullet jump alot and possibly increase accuracy
 
I tried going longer than book OAL and they fit the magazine okay but wouldn't eject if unfired. Two different makes of gun in the same calibre and they both had to be exactly the book OAL or they hung up ejecting. They would feed okay from the mag or could load and fire one at a time.
 
The OAL. In the book is an OAL that will feed /chamber in any gun in that caliber, the longer OAL you messure in your rifles are because the throat is cut longer then minimum . If you want to magazine feed, old them as long as you can to fit the mag, if you want / don't mind single feeding , load them any length you want

Keep in mind that bullet tips vary in length and if you want true / accurate measurements your much better off to get the right tools and measure off the Ogive of the bullet. Load 10 rounds and u will get 10 different measurements , when measuring off the tip
 
ultimate_monkey said:
The OAL. In the book is an OAL that will feed /chamber in any gun in that caliber, the longer OAL you messure in your rifles are because the throat is cut longer then minimum . If you want to magazine feed, old them as long as you can to fit the mag, if you want / don't mind single feeding , load them any length you want

Keep in mind that bullet tips vary in length and if you want true / accurate measurements your much better off to get the right tools and measure off the Ogive of the bullet. Load 10 rounds and u will get 10 different measurements , when measuring off the tip
Click to expand...


This is very true! Measuring to the tip of the bullet is very unreliable "if" you are trying to seat closely to the rifling lands. Get the Hornady chamber all overall length guage bushings that fit onto your calipers. They measure from the ogive of the bullet. Way more consistant!

image-11.jpg


image-10.jpg
 
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There are more threads about new reloaders having trouble with the COAL on here, than any other part of reloading.
And they are all the same, just change the figures.
In every case there is no problem!
The new reloading books have treated this COAL figure as being so critical that it has confused the new reloader into thinking he has a problem.
Forget all those figures in the books.
Seat a dumy round well out and try to close the bolt. If it won't close, push the bullet in a bit. When the bolt closes you should have the bullet in the case about 3/4 the diameter of the bullet. If this is the case, shoot away. If the bullet isn't seated that deep, seat it deeper, then shoot away.
If the bullets stick out too far to work through your magazine and you want to use your magazine, seat them a little deeper.
Use your time for reloading, instead of writing about a problem that doesn't exist.
 
dthunter said:


This is very true! Measuring to the tip of the bullet is very unreliable "if" you are trying to seat closely to the rifling lands. Get the Hornady chamber all overall length guage bushings that fit onto your calipers. They measure from the ogive of the bullet. Way more consistant!

image-11.jpg


image-10.jpg
Click to expand...

X2 - bought one last year and love it, saved me lots of time and aggravation
 
H4831 said:
There are more threads about new reloaders having trouble with the COAL on here, than any other part of reloading.
And they are all the same, just change the figures.
In every case there is no problem!
The new reloading books have treated this COAL figure as being so critical that it has confused the new reloader into thinking he has a problem.
Forget all those figures in the books.
Seat a dumy round well out and try to close the bolt. If it won't close, push the bullet in a bit. When the bolt closes you should have the bullet in the case about 3/4 the diameter of the bullet. If this is the case, shoot away. If the bullet isn't seated that deep, seat it deeper, then shoot away.
If the bullets stick out too far to work through your magazine and you want to use your magazine, seat them a little deeper.
Use your time for reloading, instead of writing about a problem that doesn't exist.
Click to expand...

I understand your aggrevation with some subjects that keep comming up over and over. But us gunnutz need to help where we can.
To the more experienced reloaders, some of us can do as H4831 says, and do it with confidence.
With allot of newer reloaders, that approach may make things a little scary.

With time spent behind the reloading press, they will get the hang of it. If they dont, some of us gunnutz will help where we can.

I aggree with H4831 that manufacuters use overall length info
Improperly.
Keep it fun guys, and keep shootin!
 
I have the same issue with my Tikkas - the 338f rifling is at 3.04" with a 200 NAB, the mag fits 2.82.... Thats a HUGE jump, just over 1/5 th of an inch, or 220 thou!!!!!! ... I did as suggested and got a different mag/bolt stop, but have yet to shoot it. I suspect thats why it doesn't shoot like the others do -
 
kwintz

I have two AR15s and a Stevens .223 bolt action with a 1 in 9 twist, the throat on my .223 is longer than the military throats in the ARs. There seems to be of late a need with gun manufactures to make chamber throats big enough to fit their company Lawyers in and still have room for the cartridge.

I also have Quickload and its amazing how seating depth can effect chamber pressure and the funny part is over at AccurateShooter.com many of the competitive shooters are jamming their bullets into the rifling. In their discussions they say the pressure is actually "lower" by jamming the bullets than if they were seated deeper into the cases. And Quickload confirms this, with a bullet seated further from the rifling the pressure builds up as the bullet moves forward then spikes higher as the bullet hits the rifling and slows down. With the bullet jammed into the rifling the chamber pressure builds more slowly and peaks further down the barrel at a lower pressure.

As long as you start low and work up you will never have a problem, I loaded some .223 ammunition with the bullets jammed into the rifling. I went up to the maximum load in my manuals and saw no signs of excess pressure and I believe this is due to the longer than normal throat.

Below, Quickload pressure esimates and the recommended manual cartridge OAL of 2.250 and a max load of 26.5 grains of 748 chamber pressure 50,976 psi

Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 55, Hornady V-MAX FB 22271-72
Useable Case Capaci: 27.080 grain H2O = 1.758 cm³
Cartridge O.A.L. L6: 2.250 inch = 57.15 mm
Barrel Length : 20.0 inch = 508.0 mm
Powder : Winchester 748

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 79 21.20 2476 749 26114 6770 81.3 1.200
-18.0 81 21.73 2541 788 27881 7023 82.9 1.170
-16.0 83 22.26 2606 829 29776 7273 84.5 1.140
-14.0 85 22.79 2671 871 31807 7517 86.0 1.111
-12.0 87 23.32 2737 915 33987 7754 87.5 1.083
-10.0 89 23.85 2804 960 36326 7985 88.9 1.055
-08.0 91 24.38 2870 1006 38840 8207 90.2 1.024
-06.0 93 24.91 2937 1054 41541 8419 91.5 0.992
-04.0 95 25.44 3004 1102 44455 8621 92.7 0.962
-02.0 97 25.97 3071 1152 47592 8812 93.8 0.933 ! Near Maximum !
+00.0 99 26.50 3139 1203 50976 8989 94.9 0.905 ! Near Maximum !
+02.0 101 27.03 3206 1256 54633 9153 95.8 0.878 !DANGEROUS LOAD-DO NOT USE!
+04.0 103 27.56 3274 1309 58590 9303 96.7 0.851 !DANGEROUS LOAD-DO NOT USE!
+06.0 105 28.09 3341 1363 62878 9437 97.4 0.826 !DANGEROUS LOAD-DO NOT USE!
+08.0 107 28.62 3409 1419 67530 9554 98.1 0.801 !DANGEROUS LOAD-DO NOT USE!
+10.0 109 29.15 3476 1476 72592 9653 98.7 0.777 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 99 26.50 3320 1346 61885 9077 99.3 0.834 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 99 26.50 2909 1034 41494 8418 86.4 0.995

Below, cartridge OAL 2.300 26.5 grains of 748 chamber pressure 48,978 psi .050 closer to the rifling and almost 2,000 psi less pressure

Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 55, Hornady V-MAX FB 22271-72
Useable Case Capaci: 27.579 grain H2O = 1.791 cm³
Cartridge O.A.L. L6: 2.300 inch = 58.42 mm
Barrel Length : 20.0 inch = 508.0 mm
Powder : Winchester 748

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 77 21.20 2456 736 25391 6766 80.9 1.213
-18.0 79 21.73 2519 775 27082 7021 82.5 1.183
-16.0 81 22.26 2583 815 28891 7273 84.1 1.153
-14.0 83 22.79 2648 856 30830 7519 85.6 1.125
-12.0 85 23.32 2713 899 32906 7760 87.1 1.096
-10.0 87 23.85 2778 942 35131 7994 88.5 1.069
-08.0 89 24.38 2843 987 37517 8220 89.8 1.039
-06.0 91 24.91 2909 1034 40076 8437 91.1 1.009
-04.0 93 25.44 2975 1081 42831 8644 92.3 0.979
-02.0 95 25.97 3042 1130 45791 8841 93.4 0.949
+00.0 97 26.50 3108 1180 48978 9025 94.5 0.921 ! Near Maximum !
+02.0 99 27.03 3175 1231 52412 9196 95.5 0.894 ! Near Maximum !
+04.0 101 27.56 3241 1283 56119 9354 96.3 0.867 !DANGEROUS LOAD-DO NOT USE!
+06.0 103 28.09 3308 1336 60124 9496 97.1 0.842 !DANGEROUS LOAD-DO NOT USE!
+08.0 105 28.62 3374 1390 64459 9623 97.8 0.817 !DANGEROUS LOAD-DO NOT USE!
+10.0 107 29.15 3440 1446 69159 9732 98.4 0.793 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 97 26.50 3289 1322 59423 9146 99.1 0.849 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 97 26.50 2879 1012 39900 8424 85.8 1.013

Quickload computes pressure and velocity estimates, and with any software you can always have garbage in = garbage out and it is no substitute for actual load development.
 
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all my tikkas have a long throat. i load them to fit and function threw the mag and they all shoot well. far too much wory on oal. if oal was so critical why does factory ammo shoot well.
 
H4831 said:
There are more threads about new reloaders having trouble with the COAL on here, than any other part of reloading.
And they are all the same, just change the figures.
In every case there is no problem!
The new reloading books have treated this COAL figure as being so critical that it has confused the new reloader into thinking he has a problem.
Forget all those figures in the books.
Seat a dumy round well out and try to close the bolt. If it won't close, push the bullet in a bit. When the bolt closes you should have the bullet in the case about 3/4 the diameter of the bullet. If this is the case, shoot away. If the bullet isn't seated that deep, seat it deeper, then shoot away.
If the bullets stick out too far to work through your magazine and you want to use your magazine, seat them a little deeper.
Use your time for reloading, instead of writing about a problem that doesn't exist.
Click to expand...
There it is again,that good old common sense stuff.
 
Hilarious... 5yrs later, new tikka same problem. Except new stainless cant shoot worth a crap. 5 moa with varying loads and bullets. Difference is nothing working this time
 
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